## Philosophy Lexicon of Arguments | |||

Modal logic: the modal logic is an extension of classical logic to systems in which possibility and necessity can also be expressed. Different approaches use operators to express "necessary" and "possible", which, depending on the placement within formulas, can let claims of different strengths win. E.g. there is an object which necessarily has the property F/it is necessary that there is an object with the property F. The introduction of possible worlds makes quantification possible for expressing possibility (There is at least one world in which ...) and necessity (For all worlds is valid ...). See also operators, quantifier, completion, range, possible worlds. | |||

Author | Item | More concepts for author | |
---|---|---|---|

Bigelow, John | Modal Logic | Bigelow, John | |

Chisholm, Roderick M. | Modal Logic | Chisholm, Roderick M. | |

Field, Hartry | Modal Logic | Field, Hartry | |

Geach, Peter T. | Modal Logic | Geach, Peter T. | |

Hintikka, J. | Modal Logic | Hintikka, J. | |

Kripke, Saul Aaron | Modal Logic | Kripke, Saul Aaron | |

Lewis, David | Modal Logic | Lewis, David | |

Quine, Willard Van Orman | Modal Logic | Quine, Willard Van Orman | |

Stalnaker, R. | Modal Logic | Stalnaker, R. | |

Ed. Martin Schulz, access date 2017-05-27 |